The present invention relates to a construction machine and, more specifically, to a construction machine in which an engine is arranged along a counter weight which is a balance weight of the construction machine.
Hydraulic excavators and wheel loaders which are typical construction machines are equipped with a counter weight at a rear end portion of a machine body to maintain a balance with the weight of working equipment installed on the front side of the machine body and with a load exerted thereon. The counter weight is so heavy that it occupies a large portion on the machine body. On the inner side of the counter weight in the machine body, an engine such as a diesel engine which is a power source of moving the construction machine is arranged along the counter weight.
The counter weight defines the contour of the rear end portion of the machine body of the construction machine. In order to maintain good rear view from the operator in a cab installed on the machine body, in order that the counter weight will not come in contact with the obstacles in the surrounding and in order to decrease the turning radius of the outside edge of the machine body, which pivots, of a construction machine such as a hydraulic excavator, therefore, it is desired to install the counter weight on the inside of the machine body as close as possible to the engine side so will not to much protrude rearward and so will not to much protrude upward, either.
The engine is equipped with heat-exchanging units such as a fan for producing the cooling air, a radiator through which the cooling air flows, an oil cooler and the like. Further, an air cleaner which is an intake air filter of the engine is installed on the side of the outside edge of the machine body opposite to the engine with the heat-exchanging units interposed therebetween in order to take in the open air of a low temperature. The construction machine is operated under severe load conditions and under severe environmental conditions. Therefore, the heat-exchanging units are formed in a large size and occupy a large space for installation on the machine body. The intake air pipe connecting the air cleaner to the engine is arranged between the heat-exchanging units and the counter weight in the portion of the heat-exchanging units or above the heat-exchanging units.
The conventional construction machine of the form as described above, however, involves problems that must be solved as described below.
(1) Rearward Protrusion of the Counter Weight
The intake air pipe of the engine has a relatively large diameter. To pass the intake air pipe between the engine and the counter weight, a piping space must be secured by broadening therebetween. For this purpose, the counter weight is moved toward the rear side of the machine body for installation. Therefore, the rear end portion of the machine body protrudes by an amount by which the counter weight is moved rearward. This gives the possibility of hindering the rear view of the operator and causing an increase in the turning radius of the outside edge of the machine body, whereby a problem will arise that the working efficiency of the construction machine deteriorates.
(2) Protruding Upward of the Machine Body
When the intake air pipe is passed above the heat-exchanging units in order to avoid protruding rearward of the counter weight, the hood of the machine body covering the upper side of the engine becomes high and the machine body protrudes further upward, hindering the rear view from the cab.
The present invention was achieved in view of the above-mentioned circumstances, and its technical assignment is to provide a construction machine in which an engine is arranged along a counter weight, wherein the intake air pipe of the engine is passed between the counter weight and the engine without the need of installing the counter weight separated away from the engine, so that protruding outward of the counter weight can be lessened.
Namely, according to the present invention, as a construction machine to solve the above-mentioned technical problems, there is provided a construction machine comprising a counter weight which is a balance weight of the construction machine, an engine arranged along the counter weight and an intake air pipe connecting the engine to an air cleaner which is an intake air filter of the engine, wherein a piping space of a recessed shape is formed in the facing surface of the counter weight facing the engine so as to pass the intake air pipe therethrough.
Further, by passing the intake air pipe through the piping space formed in the counter weight, the engine and the counter weight can be arranged without being separated away from each other.
In a preferred embodiment, the surface facing the engine is formed being curved in a direction to cover the engine.
The counter weight is so formed as to cover the engine and consequently, the weight of the engine efficiently works as a balance weight, making, as a whole, it possible to decrease the protruding rearward of the counter weight.
Further, a fan driven by the engine and a heat-exchanging unit through which the cooling air produced by the fan flows are provided, the air cleaner is installed on the side opposite to the heat-exchanging unit with respect to the engine, and the intake air pipe is arranged passing through the piping space in a portion where the heat-exchanging unit and the counter weight are neighboring each other.
By passing the intake air pipe through the piping space of the counter weight in a portion of the heat-exchanging unit that occupies a large space, the problem of protrusion of the counter weight is eliminated.